Passing Parameters by Reference

If you're accustomed to programming in VB or VBA, you'll recognize the way that you pass arguments in VBScript. However, in Versions 1 and 2 of VBScript, this wasn't the case. Parameters could be passed only by value, and there was no support for passing parameters by reference.

I suggest use return value function
check this links for information:

http://www.intranetjournal.com/articles/200009/vb4.html
http://msdn.microsoft.com/library/de...classtopic.asp